Process of extracting glycerine from fatty substances



UNITED STATES PATENT OFFICE.

JAMES H. CLINTON, OF ST. LOUIS, MISSOURI.

PROCESS OF EXTRACTING GLYCERINE FROM FATTY SUBSTANCES.

SPECIFICATION forming part of Letters Patent No. 336,795, dated February 23, 1886.

Application filed June 22, 1835.

To all whom it may concern.-

Be it known that 1, JAMES H. CLINTON, of the city of St. Louis, in the State of Missouri, have invented a certain new and useful Improvement in the Process of Extracting Glycerine from Fatty Substances, of which the following is a full, clear, and exact description.

This invention relates to an improved process of separating glycerine from animal or vegetable fatty substances; and this invention consists in features of novelty hereinafter fully described, and pointed out in the claims.

In my process I use a copper digester of usual form,about four feet in diameter by about sixteen to twenty feet long. An elongated three-inch bar or slab is suspended, preferably in the center of the digester, by a copperwire rack; but said bar may be suspended in other parts of the digester and more than one bar may be used without departing from the essential features of my invention.

The three-inch bar I describe in this process is of about forty pounds weight, as I find that is about the weight required in a digester of the above-stated dimensions; but I do not limit my invention to bars of that weight, as they may vary in weight according to the number of bars, the size of the charge, and quality of the stock.

After the suspension of the bar in the digester about six thousand pounds of fatty substance (in a digester and charge of the size stated) is then let in and one per cent. of lime slaked to the consistency of cream is added to the charge, except in soap-stock, when the lime is dispensed with. Steam is then turned on at about one hundred and forty pounds pressure, (although the pressure may be varied to the condition of the charge.) The steam preferably enters through a perforated coil at the bottom of the digester until there is about sixty pounds pressure on the charge. The steam is then turned off,'while about two thousand pounds of hot water from the boiler, at a temperature of about 300 degrees, is forced into the digester. It is an important feature in the process that the charge should be brought under sufficient pressure and sufficiently raised in temperature before the addition of the water. The steam is then again turned on at about one hundred and forty pounds pressure, and up to about 355 of tem- Serial No. 169,437.

(No specimens.)

perature, and kept on for about five or six hours, when the saponification is completed in about half the time it takes in the old lime L this time at between 5 and 6 of strength, is

evaporated until the residue is at about 28, the specific gravity of glycerine.

The zinc bar, especially when suspended in the center of the charge, perfectly diffuses its influence throughout the whole of the stock in the digester, avoiding the difficulty experienced by the unequal and only partial diffusion of its influence when the zinc is used in granulated or any other form in which it deposits itself on the bottom of the digester, and consequently misses much of its desired effect on the remote portion of the stock.

The zinc bar in my process lasts for six months with two charges per day-a feature of importance when considered relatively with systems and processes in which there has to be a renewal at each charge; also, by this process the saponification of the stock is so thoroughly effected that the market value of the glycerine is one and a half'to two cents per pound in advance of other stock previous to refining, being not only purer, but also paler in color and finer in quality. The fatty stock is also much firmer and more waxy in its nature and whiter in color, in consequence of the more complete extraction of the glycerine and the reduction of time that it is under the influence of the superheated steam.

The digester in this process keeps clean and free from sediment-a great advantage over other processes, where it has to be frequently cleaned out. Only one percent. of lime is required, instead of three per cent., as in the usual lime processesa valuable feature, as although it is perhaps impossible to attain the bestresults without a slight percentage of lime, yet if much in excess of the formula here presented the residuary effect of the lime after having performed its intended function is detrimental in both the glycerine and fatty stock, and, as previously stated, I obtain the best results in soap-stocks without the use of lime.

The fatty stock, even from cotton-seed and ICC without any change in the usual lime process digester. It is found to be of advantage to have no vent for escaping steam, but to condense the same within the digester, as there is great loss with steam escaping under one hundred and forty pound pressure.

I claim as my invention- 1. The process of extracting glycerine from fatty substances, consisting in placing the fatty substance in a close digester with a zinc bar suspended therein, with the addition of about one per cent. of lime and a suitable amount of water, forcing steam into the char e for about five and one-halfhou rs, until the saponification of the stock is completed, all substantially as described, and for the purpose set forth.

2. The process of extracting glycerine from fatty substances, consisting in placing the fatty substance and about one per cent. of slaked lime in a close digester in which a zinc bar is centrally suspended, forcing steam into the charge, turning off steam and adding asuitable amount of water, again turning on the steam at a pressure of about one hundred and forty pounds, until the saponification of the stock,all substantially as described, and for the purpose set forth. n

3. The process of extracting glycerine from fatty substances, consisting in placing the fatty substance, with a small per cent. of slaked lime, in a digester with a zinc bar suspended therein, turning on steam into the digester, adding a suitable amount ofwater, retaining a steam-pressure of about one hundred and forty pounds, and confining and condensing the steam Within the digester, all substantially as described, and for the purpose set forth, until the saponification of the stock.

4. The process of extracting glycerine from fatty substances, consisting in placing the fatty substance, with about one per cent. of slaked lime with a suitable amount of Water, in a digester that has a zinc bar suspended therein, forcing steam through the charge to insure its saponification, condensing steam Within the digester, blowing off the glycerine-Water into an eva1: orating-tank, and, lastly, evaporating the glycerine-water to its desired specific gravity, all substantially as described, and for the purpose set forth.

5. The process of extracting glycerine from fatty substances, consisting in placing the fatty substance in a digester in which a zinc bar is suspended, adding about one per cent. of slaked lime and a suitable amount of Water, turning on about one hundred and fortypounds of steam-pressure, until the saponification of the charge, and, lastly, blowing off the glycerine water into an evaporating tank, and evaporating the superfluous water, allsubstantially as described, and for the purpose set forth.

6. The process of extracting glyceriue from fatty substances for soap stock, &c., consisting in placing the fatty substance in a digester in which a zinc bar is suspended, bringing the charge under steam-pressure, turni n g off steam and adding a suitable amount of water, again turning on about one hundred and forty pounds of steam-pressure and retaining it under pressnre until the saponification of the stock, and, lastly, blowing off the glycerine-water into an evaporating-tank and evaporating the super fluous water, all substantially as described, and for the purpose set forth.

JAMES H. CLINTON.

In presence of BENJN. A. KNIGHT, GEO. H. KNIGHT. 

